1. Department of Physics, The George Washington University , Washington, DC 20052 , USA
2. Department of Astronomy, University of Maryland , College Park, MD 20742-4111 , USA
3. Astrophysics Science Division, NASA Goddard Space Flight Center , 8800 Greenbelt Road, Greenbelt, MD 20771 , USA
4. Faculty of Engineering and Natural Sciences, SabancıUniversity , İstanbul 34956 , Turkey
5. Center for Research and Exploration in Space Science and Technology, NASA/GSFC , Greenbelt, MD 20771 , USA
6. Department of Physics, The Catholic University of America , 620 Michigan Avenue, N. E. Washington, DC 20064 , USA
7. CRESST II and X-ray Astrophysics Laboratory, NASA/GSFC , Greenbelt, MD 20771 , USA
8. Department of Physics, University of Maryland Baltimore County , 1000 Hilltop Circle, Baltimore MD 21250 , USA
9. SRON Netherlands Institute for Space Research , Niels Bohrweg 4, NL-2333CA Leiden , the Netherlands
10. Department of Astronomy, University of Cape Town , Private Bag X3, Rondebosch 7701 , South Africa
11. South African Astronomical Observatory , PO Box 9, Observatory, 7935 Cape Town , South Africa
12. Southern African Large Telescope , PO Box 9, Observatory, 7935 Cape Town , South Africa
13. Department of Physics, University of the Free State , PO Box 339, Bloemfontein 9300 , South Africa
14. Department of Astrophysics/IMAPP, Radboud University , NL-6525 AJ Nijmegen , The Netherlands
15. Department of Physics and Astronomy – MS 108, Rice University , 6100 Main Street, Houston, TX 77251-1892 , USA
16. DIRAC Institute, Department of Astronomy, University of Washington , 3910 15th Avenue NE, Seattle, WA 98195 , USA
17. Joint Space-Science Institute, University of Maryland , College Park, MD 20742 , USA
18. School of Physics and Astronomy, University of Leicester , University Road, Leicester, LE1 7RH , UK
19. Department of Natural Sciences, The Open University of Israel , PO Box 808, Ra’anana 43537 , Israel
20. Astrophysics Research Center of the Open university (ARCO), The Open University of Israel , PO Box 808, Ráanana 43537 , Israel
21. Columbia Astrophysics Laboratory, Columbia University , New York, NY 10027 , USA
22. Cahill Center for Astrophysics, California Institute of Technology , 1216 East California Boulevard, Pasadena, CA 91125 , USA
23. Department of Physics and Astronomy, Clemson University , Kinard Lab of Physics, Clemson, SC 29634-0978 , USA
24. Anton Pannekoek Institute for Astronomy, University of Amsterdam , Science Park 904, NL-1098 XH Amsterdam , the Netherlands
25. Department of Astronomy and Astrophysics, The Pennsylvania State University , 525 Davey Lab, University Park, PA 16802 , USA
26. Department of Physics, University of Johannesburg , PO Box 524, Auckland Park 2006 , South Africa
27. Center for Astrophysics, Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138 , USA
28. Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive, Mail Stop 169-221, Pasadena, CA 91109 , USA
29. Anton Pannekoek Institute, University of Amsterdam , Postbus 94249, NL-1090 GE Amsterdam , the Netherlands